( 164 ) 



There is no evidence of a smooth course, bul rather a sudden 

 increase about the XI V^'' or XV^ii century. If there was any question 

 of slowly increasing refrigeration, this would appear most clearly 

 between the XV' and XIX^'» century, the material being more 

 complete during this time. 



For the three 356-year periods treated in Table I, First Commu- 

 nication, the numbers are: 25, 37 and 66. When treating this table 

 with the weights 4, 6, 10 for the 1»^ , 2"^' and 3''J "great period" we 

 obtain for the totals (see Table VII and fig. 1, f b): 



I (848—1203) 1.6 4.8 2.0 2.4 2.8 2.0 0.8 



II (1204—1560) 1.8 6.9 10.8 3.6 5.4 3.6 4.8 1.8 



III (1561—1916) 24. 18.0 15.0 14.0 23.0 16.0 11.0 4.0 



Total .... 27 30 28 20 31 22 16 7~ 



In the recent material the depression about the middle of the 

 89-year period is pretty evident; we must remark however that it is 

 not to be found in the even 89-year periods of Table I; the totals 

 for the even periods separately become: 



14, 17, 11, 12, 11, 10, 4, 3. 



This may be attributed of course to a 356-year period, in which, 

 as appears from the table, the third 89-year subperiod is strongly 

 anomalous. 



I will now try to summarise the main I'esults of the investigation 

 contained in these two communications. 



We have seen — particularly when investigating the 11-year 

 cycles, leaving out of account their connection with any longer period — 

 that the purer our data the more evident the correlation between 

 modifications of the sun's activity and the deviations of the climate. In the 

 same degree however these data become more scanty and the acci- 

 dental deviations might perhaps have a predominant influence for 

 this reason. 



In these circumstances the first of our final conclusions must be this : 

 our data are insufficient for any rigid proof. 

 In regard to each several part of the investigation, we can at most 

 qualify them as strong indications. 



For some points, however, these indications take?! together are so 

 strong that they may be considered convincing. Such is to my opinion 

 first, the existence of a fluctuation, both in the activity of the sun 

 and in the climate, larger than the well known 11-year cycle of 

 the sun spots. 



This conclusion, though very probable, would not seem to be demon» 



